Known waveguide assemblies include a plurality of waveguides which are screwed to each other via standardized end flanges. For eliminating excessive heat, cooling pipes are provided which are soldered to the side walls of the waveguides and extend parallel to the longitudinal axis of the latter. The cooling pipes of adjoining waveguides are connected to each other via short pipe bends or tube bends interposed between the angled ends of the cooling pipes.
Such cooled waveguide assemblies are used for transmitting rf-powers in the megawatt range. The time consuming and expensive manufacture of the waveguides and their assembly to a waveguide system is, however, disadvantageous. Further drawbacks reside in the different thermal expansion of the used materials of the waveguide and the cooling pipes so that e.g. with the increased number of required joints of cooling pipes a growing danger of leakages and an irregular cooling especially at the area of the flange connections are obtained thereby limiting the transmittable rf-power. Another drawback is the annealing of waveguides when brazing the flanges.